The carbonyl group is a structural motif common in a diverse range of natural products and pharmaceutical agents used to treat human diseases. This project involves the systematic expansion of hydroacylation as an ideal and powerful strategy for making carbonyl-containing compounds, including both esters and ketones. This innovative approach will lead to step- and atom-economical, sustainable, and stereoselective methods that greatly bolster our ability to access molecules relevant to human health, including enantiopure heterocycles and polyketides. In addition, these studies will provide efficient ways to make building blocks that can be elaborated to bioactive structures. Besides the practical value, this project will provide fundamental insights into the use of various catalysts, including rhodium, ruthenium, cobalt, and nickel, for the activation and functionalization of carbon-hydrogen bonds-a long standing challenge in modern organic chemistry.